Skull Practice

1. Fill in the total number of bones for the Cranium and Facial Bones

Cranium: 8 Facial Bones: 14

2. List the four cranial bones that form that calvaria (skull cap)

Frontal, Right Parietal, Left Parietal, Occipital

3. List the four cranial bones tha form the floor of the cranium

Right temporal Left temporal Sphenoid Ethmoid

7. The small horizontal plate of the ethmoid is called the

Cribriform plate

8. The vertical plate of the ethmoid bone forming the upper portion of the bony nasal septum is the

Perpendicular plate

10. A structure found in the middle of the sphenoid bone that surrounds the pituitary gland is the

Sella turcica

11. The posterior aspect of the sella turcica is called the ________________________

Dorsum sellae

12. Which structure of the sphenoid bone allows for the passage of the optic nerve and is the actual opening into the orbit? ________________________

Optic Foramen

13. Which structures of the sphenoid bone help to form part of the lateral walls of the nasal cavities? ________________________

Medial and Lateral Pterygoid Processes

14. Which radiographic projection best demonstrates the sella turcica and dorsum sellae?

Lateral Projection

15. Which aspect of the frontal bone forms the superior aspect of the orbit?

Oribital or horizontal portion

17. Cranial sutures are classified as being __________________ joints.

Fibrous or synarthrodial

18. Small, irregular bones that sometimes develop in adult skull sutures are called __________________ or __________________ bones and are most frequently found in the __________________ suture.

Sutural or wormian; lambdoidal

19. Which term describes the superior rim of the orbit? (Include the abbreviation also.)

Supraorbital margin (SOM)

20. What is the name of the notch that separates the orbital plates from each other?

Ethmoidal Notch

21. Which cranial bones form the upper lateral walls of the calvarium?

Right and left parietals

22. Which cranial bone contains the foramen magnum?

Occipital

23. A small prominence located on the squamous portion of the occipital bone is called the __________________.

External occipital protuberance, or inion

24. What is the name of the oval processes found on the occipital bone that help form the atlanto-occipital joint?

Occipital condyles, or lateral condylar portions

25. List the three aspects of the temporal bones.
    A. __________________
    B. __________________
    C. __________________

Squamous, Mastoid, Petrous

26. True/False: The mastoid portion of the temporal bone is the densest of the three aspects of the temporal bone.

False (Petrous Portion)

27. Which external landmark corresponds with the level of the petrous ridge?

Top of the ear attachment (TEA)

28. Which opening in the temporal bone serves as a passageway for nerves of hearing and equilibrium?

Internal acoustic meatus

1B. List the three aspects of the temporal bone:

Squamous, Mastoid, Petrous

2b. Which aspect of the temporal bone is considered the densest?

Petrous portion

3b. Which structure makes up the cartilaginous external ear?

Auricle or pinna

4b. How long is the average external acoustic meatus (EAM)?

1 inch (or 2.5cm)

5b. Which small membrane marks the beginning of the middle ear?

Tympanic membrane (eardrum)

6b. What is the collective term for the small bones of the middle ear?

Auditory ossicles

7b. Which structure allows for communication between the nasopharynx and middle ear?

Eustachian or auditory tube

8b. What is the major function of the structure described in Question 7?

To equalize the atmospheric pressure within the middle ear

9b. Which structure serves as an opening between the mastoid portion of the temporal bone and the middle ear?

Aditus

10b. What is the name of the thin plate of bone that separates the mastoid air cells from the brain?

Tegmen tympani

11b. Which of the auditory ossicles picks up sound vibrations from the tympanic membrane?

Malleus (Hammer)

12b. Which of the auditory ossicles is considered the smallest?

Stapes (Stirrup)

13b. Which of the auditory ossicles resembles a premolar tooth?

Incus (Anvil)

14b. What is the name of the small membrane that connects the middle to the inner ear?

Oval or vestibular window

15b. Which two sensory functions occur within the inner ear?

Hearing and Equilibrium

16b. What is the name of the small membrane found at the base of the cochlea (two terms possible)?

Round or cochlear window

17b. True/False: The semicircular canals include a closed system specific to the sense of hearing.

False

19b. Match each of the following clinical indications for the temporal bone to the correct definition or description: Neoplasia

New and abnormal growth

19b. Match each of the following clinical indications for the temporal bone to the correct definition or description: Otosclerosis

Hereditary disease involving excessive bone formation of middle ear

19b. Match each of the following clinical indications for the temporal bone to the correct definition or description: Mastoiditis

Bacterial infection of the mastoid process

19b. Match each of the following clinical indications for the temporal bone to the correct definition or description: Acoustic Neuroma

Benign tumor of the auditory nerve sheath

19b. Match each of the following clinical indications for the temporal bone to the correct definition or description: Polyp

Growth arising from a mucous membrane

19b. Match each of the following clinical indications for the temporal bone to the correct definition or description: Cholesteatoma

Benign, cystic mass or tumor of the middle ear

20b. Which of the following radiographic appearances pertains to an acoustic neuroma?

Expansion of the internal acoustic canal

21b. Is CT the best imaging modalities that demonstrates otosclerosis?

Yes

Is the middle nasal conchae a facial bone?

No

2c. What is the largest immovable bone of the face?

Maxilla

3c. List the four processes of the maxilla.

Frontal process, Zygomatic process, Alveolar process, Palatine process

4c. Which of the processes mentioned in Question 3 is considered most superior?

Frontal process

5c. Which soft tissue landmark is found at the base of the anterior nasal spine?

Acanthion

6c. Which facial bones form the posterior aspect of the hard palate?

Horizontal portion of the palatine bones

7c. Which two cranial bones articulate with the maxilla?

Frontal and ethmoid

8c. Which facial bones are sometimes called the "cheek bones"?

Zygomatic or malar bones

9c.Does the mandible articulate with the zygomatic bone?

No, it articulates with the TMJ

10c. Which facial bone is associated with the tear ducts?

Lacrimal bones

11c. The purpose of the __________, or ___________, is to divide the nasal cavity into compartments and to circulate air coming into the nasal cavities.

Conchae; turbinates

12c. True/False: The right and left nasal bones form the largest part of the nose.

False (Most of the nose is composed of cartiliage)

13c. A deviated nasal septum is most likely to occur at the junction between _______ and _______

Septal cartilage, vomer (pushed laterally to one side)

14c. Match each of the following mandibular terms to the correct definition or description: A. Gonion

Mandibular Angle

14c. Match each of the following mandibular terms to the correct definition or description: Mandibular Notch

U-shaped notch

14c. Match each of the following mandibular terms to the correct definition or description: Body

Horizontal portion of mandible

14c. Match each of the following mandibular terms to the correct definition or description: Condyloid Process

Posterior process of the upper ramus

14c. Match each of the following mandibular terms to the correct definition or description: Coronoid Process

Bony process located anterior to mandibular notch

14c. Match each of the following mandibular terms to the correct definition or description: Ramus

Vertical portion of mandible

14c. Match each of the following mandibular terms to the correct definition or description: Mentum

Chin

14c. Match each of the following mandibular terms to the correct definition or description: Symphysis Menti

Point of union between both halves of the mandible

15c. The single facial bone and the one pair of facial bones not visible from the exterior and not demonstraed in Figs 11.18 and 11.19 are the __________ and the ___________ respectively.

Vomer; paleatine bones inferior surface view of the maxillae

20c. From anterior to posterior, the cone-shaped orbits project upward at an angle of _______ and toward the midsagittal plane at an angle of ________.

30 degrees, 37 degrees

21c. Which facial bone opening has the maxillary branch of the fifth cranial nerve passing through it?

Inferior orbital fissure

22c. Which of the facial bone openings is formed by a cleft between the greater and lesser wings of the sphenoid bone?

A. Superior orbital fissure

23c. What is another term for the second cranial nerve?

Optic nerve

1d. What is the older term for the maxillary sinuses?

Antrum, antrum of Highmore

2d. An infection of the teeth may travel upward and involve the _________ sinus.

Maxillary

3d. Specifically, where are the frontal sinuses located

Between the inner and outer tables of the skull, posterior to the glabella

4d. The frontal sinuses rarely become aerated before the age of _________

6 years

5d. Which specific aspect of the ethmoid bone contains the ethmoid sinuses?

Lateral masses or labyrinths

6d. The drainage pathway for the paranasal sinuses is called the:

Ostiomeatal complex

7d. Which sinus is projected through the open mouth with a PA axial transoral projection?

Sphenoid sinus

10d. What is the name of the passageway betweent the maxillary sinuses and the middle nasal meatus?

Infundibulum

11d. True/False: Most CT studies of the paranasal sinuses do not require the use of contrast media.

True

12d. Which position is most often used when performing a CT study of the sinuses?

Prone

1e. What are the three classifications of the skull?

Mesocephalic, Brachycephalic, Dolichocephalic

1e. What classification fits the width <75% of length?

Dolichocephalic

1e. What classification fits the width >= 80% of length?

Brachycephalic

1e. What classification fits the width between 75% and 80% of length?

Mesocephalic

2e. Central ray angles and degree of rotation stated for basic skull positions are based on the ___________ skull, which has an approximate angle of __________ between the midsagittal plane and the long axis of the petrous bone.

Mesocephalic, 47 degrees

3e. The long, narrow-shaped skull has an angle of approximately _______ between the midsagittal plane and the long axis of the petrous bone.

±40 (<47 degrees)

4e. True/False: Skull morphology has no impact on positioning considerations.

False (CR angles and head rotations may be different)

5e. There is a _______ difference between the orbitomeatal and infraorbitomeatal lines, and _______ between the orbitomeatal and glabellomeatal lines.

7–8 degrees; 7–8 degrees (same degrees of difference

6e. Match each of the following cranial landmarks and positioning lines with the correct definition: Lateral junction of the eyelid

Outer Canthus

6e. Match each of the following cranial landmarks and positioning lines with the correct definition: Posterior angle of the jaw

Glabelloalveolar Line (GAL)

6e. Match each of the following cranial landmarks and positioning lines with the correct definition: A line between the infraorbital margin and the EAM

Infraorbitometal Line (OML)

6e. Match each of the following cranial landmarks and positioning lines with the correct definition: Corresponds to the highest “nuchal” line of the occipital bone

Inion

6e. Match each of the following cranial landmarks and positioning lines with the correct definition: A line between the glabella and alveolar process of the maxilla

Glabelloalveolar Line (GAL)

6e. Match each of the following cranial landmarks and positioning lines with the correct definition: A line between the mental point and EAM

Mentomeatal Line

6e. Match each of the following cranial landmarks and positioning lines with the correct definition: Located at the junction of the two nasal bones and the frontal bone

Nasion

6e. Match each of the following cranial landmarks and positioning lines with the correct definition: The small cartilaginous flap covering the ear opening

Tragus